Actuation and valve mechanism

ABSTRACT

The invention provides a cable drive device ( 10 ) including a linear drive member ( 12 ), and a cable drum ( 14 ) attached to a support bracket ( 30, 32 ) adapted to be affixed to a surface. The cable drum ( 14 ) has an axle ( 26 ) supported by the support bracket ( 30, 32 ) to allow rotation of the cable drum ( 14 ). The cable drum ( 14 ) has a cable ( 42 ) affixed at either end of said linear drive member ( 12 ) and tautly wrapped around the cable drum ( 14 ). The cable drum ( 14 ) is located between the ends of the linear drive member ( 12 ) to, in use, allow the linear drive member ( 12 ) to be guided through the bracket ( 30, 32 ) to move the linear drive member ( 12 ) longitudinally when the axle ( 26 ) is rotated.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.14/009,331, filed Nov. 8, 2013 and entitled “Actuation and ValveMechanism,” which is a national stage application pursuant to 35 U.S.C.§371 of International Application No. PCT/AU2012/000328, filed Mar. 30,2012, which claims priority to Australian Patent Application No.2011901214, filed Apr. 1, 2011, which are hereby incorporated byreference herein.

BACKGROUND OF THE INVENTION

The present invention relates to fluid control barriers and actuationmechanisms, which can be incorporated into such barriers, but notlimited to irrigation environments.

SUMMARY OF THE INVENTION

The present invention in one embodiment provides a fluid control barrieradapted to be fitted to an end of a pipe or inside said pipe throughwhich fluid is contained or inside a pipe through which fluid flows, abi-foldable barrier member controls movement of said fluid, saidbi-foldable barrier member having a pair of plates with a hinge alongtheir straight edges to allow for opening and closing of said fluidcontrol barrier, at least one pair of struts pivotally mounted to saidplates at one end and pivotally attached to a fixed position shaft orcross member at the other end thereof, said struts mounted to saidplates along or near to the centroidal axes of said plates to minimizethe force required to open or close said bi-foldable barrier member.

Preferably an actuation member is attached to said hinge to provide apush and pull movement of said hinge to allow said bi-foldable barriermember to be opened and closed.

The invention also provides in a further embodiment a cable drive deviceincluding a linear drive member, a cable drum attached to a supportbracket adapted to be affixed to a surface, said cable drum having anaxle supported by said support bracket to allow rotation of said cabledrum, said cable drum having a cable affixed at either end of saidlinear drive member and tautly wrapped around said cable drum, saidcable drum located between said ends of said linear drive member to, inuse, allow said linear drive member to be guided through said bracket tomove said linear drive member longitudinally when said axle is rotated.

In yet a further embodiment there is provided a cable drive deviceincluding an arcuate segment drive member, a cable drum having an axleto allow rotation of said cable drum, said cable drum having a cableaffixed at either end of the arcuate section of said arcuate segmentdrive member and tautly wrapped around said cable drum, said cable drumlocated between said ends of said arcuate section of said arcuatesegment drive member to, in use, allow said arcuate segment drive memberto be moved when said axle is rotated.

A further embodiment provides a control gate adapted to be installedacross a flow channel for liquids, said control gate having a barriermember that is pivotally mounted at or adjacent the base of said flowchannel and at least one drive means to raise and lower said barriermember, said at least one drive means comprising a cable drive device asdisclosed herein, wherein one of said ends of said linear drive memberis pivotally attached to said barrier member.

The invention may also provide a fluid control barrier adapted to befitted to an end of a pipe through which fluid is contained, a framemember is mounted on said end of said pipe, a barrier member ispivotally mounted one a first edge to said frame member to allow foropening and closing of said fluid control barrier and at least one cabledrive device as disclosed herein is fixed to said frame member and saidbarrier member to allow said barrier member to be opened and closed.

Another embodiment provides a fluid control barrier adapted to be fittedto an end of a pipe through which fluid is contained, a frame member ismounted on said end of said pipe, a bi-foldable barrier member closessaid end of said pipe, said bi-foldable barrier member having a pair ofplates with a hinge along their straight edges to allow for opening andclosing of said fluid control barrier, said hinge pinned to said framemember or said pipe and a pair of lifting means attached to each of saidplates to allow said bi-foldable barrier member to be opened and closed.

In a practical embodiment there is provided a fluid control barrieradapted to be fitted inside a pipe through which a fluid flows, abi-foldable barrier member is provided to control fluid flow throughsaid pipe, said bi-foldable barrier member having a pair of plates witha hinge along their straight edges to allow for opening and closing ofsaid fluid control barrier, said hinge pinned to said pipe and a pair oflifting means attached to each of said plates to allow said bi-foldablebarrier member to be opened and closed.

BRIEF DESCRIPTION OF THE DRAWINGS

The structure and functional features of preferred embodiments of thepresent invention will become more apparent from the following detaileddescription when taken in conjunction with the accompanying drawings, inwhich:

FIG. 1 is a perspective view of a first embodiment of a cable drivedevice made in accordance with the invention;

FIG. 2 is an enlarged perspective view of the cable drum of FIG. 1showing the position of the cable co-operating with the cable drum;

FIG. 3 is a side view of the cable drive device shown in FIG. 1;

FIG. 4 is a front view of the cable drive device shown in FIG. 1;

FIG. 5 is a cross-sectional view along and in the direction of arrows5-5 shown in FIG. 4;

FIG. 6 is a similar view to that of FIG. 5 showing a second embodimentof a cable drive device made in accordance with the invention;

FIG. 7 is a perspective view of an irrigation channel showing the use ofthe cable drive device of FIG. 1 attached to an overshot control gate tocontrol the flow of water in the irrigation channel;

FIG. 8 is a similar view to that of FIG. 7 showing the use of a pair ofcable drive devices of the type shown in FIG. 1;

FIG. 9 is a side view of FIG. 7 showing the control gate closed;

FIG. 10 is a similar view to that of FIG. 9 showing the control gate ina partially open position;

FIG. 11 is a similar view to that of FIG. 10 showing the control gate ina fully open position;

FIG. 12 is a perspective view of a further irrigation channel showingthe use of the cable drive device of FIG. 1 attached to a control gateto control the flow of water in the irrigation channel;

FIG. 13 is a similar view to that of FIG. 12 showing the use of a pairof cable drive devices of the type shown in FIG. 1;

FIG. 14 is a side view of FIG. 12 showing the control gate closed;

FIG. 15 is a similar view to that of FIG. 14 showing the control gate ina partially open position;

FIG. 16 is a similar view to that of FIG. 15 showing the control gate ina fully open position;

FIG. 17 is a perspective view of a fluid control barrier made inaccordance with the invention and fitted to the end of a pipe with thefluid control barrier shown in the closed position;

FIG. 18 is a front view of FIG. 17;

FIG. 19 is a side view of FIG. 17;

FIG. 20 is a similar view to that of FIG. 17 with the fluid controlbarrier shown in the open position;

FIG. 21 is a front view of FIG. 20;

FIG. 22 is a side view of FIG. 20;

FIG. 23 is a perspective view of a fluid control barrier made inaccordance with the invention and fitted to the end of a pipe with thefluid control barrier shown in the closed position using the cable drivedevices as shown in FIG. 1;

FIG. 24 is a front view of FIG. 23;

FIG. 25 is a side view of FIG. 23;

FIG. 26 is a similar view to that of FIG. 23 with the fluid controlbarrier shown in the open position;

FIG. 27 is a front view of FIG. 26;

FIG. 28 is a side view of FIG. 26;

FIG. 29 is a perspective view of a fluid control barrier made inaccordance with the invention and fitted inside a pipe with the fluidcontrol barrier shown in the open position which uses a cable drivedevice as shown in FIG. 1;

FIG. 30 is a side view of FIG. 29 with a cutaway to show the operationof the fluid control barrier;

FIG. 31 is a perspective view of a fluid control barrier made inaccordance with the invention and fitted to the end of a pipe with thefluid control barrier shown in the closed position;

FIG. 32 is a front view of FIG. 31;

FIG. 33 is a side view of FIG. 31;

FIG. 34 is a similar view to that of FIG. 31 with the fluid controlbarrier shown in the open position;

FIG. 35 is a front view of FIG. 34;

FIG. 36 is a side view of FIG. 34;

FIG. 37 is a perspective view of a fluid control barrier made inaccordance with the invention and fitted to the end of a pipe with thefluid control barrier shown in the closed position;

FIG. 38 is a front view of FIG. 37;

FIG. 39 is a side view of FIG. 37;

FIG. 40 is a similar view to that of FIG. 37 with the fluid controlbarrier shown in the open position;

FIG. 41 is a front view of FIG. 40;

FIG. 42 is a side view of FIG. 40;

FIG. 43 is a perspective view of a circular drive device made inaccordance with a preferred embodiment of the invention;

FIG. 44 is a front view of the circular drive device shown in FIG. 43 ina rotated position;

FIG. 45 is a perspective cutaway view of a fluid control barrier made inaccordance with the invention and fitted inside a pipe with the fluidcontrol barrier shown in the closed position;

FIG. 46 is a similar view to that of FIG. 45 with the fluid controlbarrier shown in the open position;

FIG. 47 is a plan view of a fluid control barrier shown in FIG. 45;

FIG. 48 is a plan view of a fluid control barrier shown in FIG. 46;

FIG. 49 is a perspective cutaway view of a fluid control barrier made inaccordance with the invention and fitted inside a pipe with the fluidcontrol barrier shown in the closed position;

FIG. 50 is a similar view to that of FIG. 49 with the fluid controlbarrier shown in the open position;

FIG. 51 is a plan view of a fluid control barrier shown in FIG. 49; and

FIG. 52 is a plan view of a fluid control barrier shown in FIG. 50;

FIG. 53 is a perspective view of a fluid control barrier made inaccordance with the invention and fitted to the end of a pipe with thefluid control barrier shown in the closed position;

FIG. 54 is a cross-sectional view along and in the direction of thearrows shown in FIG. 55;

FIG. 55 is a front view of the fluid control barrier shown in FIG. 53;

FIG. 56 is a side view of FIG. 55;

FIG. 57 is similar view to that of FIG. 53 showing the fluid controlbarrier starting to open;

FIG. 58 is a cross-sectional view along and in the direction of thearrows shown in FIG. 59;

FIG. 59 is a front view of the fluid control barrier shown in FIG. 57;

FIG. 60 is a side view of FIG. 59;

FIG. 61 is similar view to that of FIG. 53 showing the fluid controlbarrier completely open;

FIG. 62 is a cross-sectional view along and in the direction of thearrows shown in FIG. 63;

FIG. 63 is a front view of the fluid control barrier shown in FIG. 61;

FIG. 64 is a side view of FIG. 61;

FIG. 65 is a plan view of a preferred bi-foldable barrier member shownin the closed position;

FIG. 66 is an end view of the barrier member shown in FIG. 65;

FIG. 67 is a side view of the barrier member shown in FIG. 65;

FIG. 68 is a cross-sectional view along and in the direction of thearrows shown in FIG. 67;

FIG. 69 is a perspective view of the barrier member shown in FIG. 65;

FIG. 70 is a plan view of the barrier member shown in FIG. 65 in thehalf-closed position;

FIG. 71 is an end view of the barrier member shown in FIG. 70;

FIG. 72 is a side view of the barrier member shown in FIG. 70;

FIG. 73 is a cross-sectional view along and in the direction of thearrows shown in FIG. 72;

FIG. 74 is a perspective view of the barrier member shown in FIG. 70;

FIG. 75 is a plan view of the barrier member shown in FIG. 65 in thefully open position;

FIG. 76 is an end view of the barrier member shown in FIG. 75;

FIG. 77 is a side view of the barrier member shown in FIG. 75;

FIG. 78 is a cross-sectional view along and in the direction of thearrows shown in FIG. 77; and

FIG. 79 is a perspective view of the barrier member shown in FIG. 75.

DESCRIPTION OF THE EMBODIMENTS

In order to avoid duplication of description, identical referencenumerals will be shown, where applicable, throughout the illustratedembodiments to indicate similar integers.

In the drawings a first embodiment is shown in FIGS. 1 to 5, which showsa cable drive device 10 having a linear drive member 12 and cable drum14. Linear drive member 12 has a longitudinal base member 16 with a pairof arms 18, 20. A pair of pivot pins 22, 24 are provided at each end forattachment to a respective member as described in subsequentembodiments. Cable drum 14 has a central axle 26 rotatably held by ajournal or bearings 28 in a support member 29. Arms 18, 20 may, ifrequired, be substituted by a longitudinal bar or plate.

A pair of faceplates 30, 32 support journal or bearings 28 at theopposite end thereof by pins 34, 36. Pins 34, 36 will, in use, slidealong base member 16 with the cable drum 14 being on one side of thelinear drive member 12 and pins 34, 36 on the other side. Pins 34, 36will prevent cable drum 14 from leaving the face of linear drive member12. Rollers can replace pins 34, 36, for reducing frictional resistance.The pair of pins 34, 36 can be substituted by a single pin or roller,which would be preferably centrally located between the positions ofpins 34, 36. Cable drum 14 has spiraled grooves 38 in its outercircumferential face 40 to allow a cable 42 to be wound out or wound outfrom cable drum 14. Cable 42 is held taut and is coupled to pivot pins22, 24 at opposite ends of linear drive member 12. Cable 42 is threadedthrough a hole 44 in cable drum 14 passing diagonally there through fromopposing outer edges of outer circumferential face 40. Cable 42 ispre-tensioned above the maximum design load of cable drive device 10. Asonly a single cable 42 is provided with multiple wraps around cable drum14, cable 42 is not subject to slip.

Cable drive device 10 can provide movement of a member by attachingeither pivot pins 22, 24 to a member to be moved and anchoring supportmember 29 to a stationary support. Rotation of central axle 26 willresult to longitudinal movement of linear drive member 12 throughsupport member 29 by the roll on or roll off movement of cable 42 aroundcable drum 14. Cable drive device 10 can generally replace devices usedfor a rack and pinion type of movement.

FIGS. 43 and 44 illustrate a similar cable drive device shown in FIGS. 1to 5 where an arcuate or circular drive member 206 replaces linear drivemember 12. Cable 42 is similarly attached to pivot pins 22, 24 and isheld taut in groove 208 of arcuate or circular drive member 206. Cabledrum 14 sits inside of groove 208 and can be supported by a bracket (notshown) and/or by axle 26. The arcuate or circular drive member 206 isshown as extending for angle X° where X can be any angle up to about360°. The arcuate or circular drive member 206 will rotate about acentral axis 210. Cable drum 14 will be configured in a similar mannerto that described with reference to FIGS. 1 to 5. This embodiment willsimulate a pinion gear (cable drum 14) driving a larger circular gear(arcuate or circular drive member 206). In use, the radial base 216 canbe attached to a movable member, for example, the top of a flap valveand the flap valve can pivot about central axis 210. Axle 26 can besupported by a frame member and axle 26 can be rotated to allow radialbase 216 to be move about central axis 210 as shown in FIG. 44. Thismovement will lift the flap valve to open the valve.

FIG. 6 illustrates an enhancement of the cable drive device 10 shown inFIGS. 1 to 5. In this embodiment a pair of linear drive members 12, 12Aon opposite sides of cable drum 14 are provided. Separate spiraledgrooves (not shown) are formed in the circumferential face of cable drum14 to allow cables 42, 42A to co-operate with cable drum 14. Theoperation of linear drive member 12A is identical to that of lineardrive member 12 discussed with reference to FIGS. 1 to 5. Because thelinear drive members 12, 12A are on opposite sides of cable drum 14 andhave opposing displacements, the movement of linear drive member 12 inone direction will cause movement of linear drive member 12A in theopposite direction on rotation of axle 26. This movement will allowgreater linear movement between pivot pins 22, 24A.

FIG. 7 shows the use of the cable drive device 10 shown in FIGS. 1 to 5in an irrigation system. A barrier member 46 is hinged at the bed orbase 48 of a channel 50 through which water passes. Barrier member 46includes a base member 52 and side members 54, 56. Barrier member 46 maybe of a rigid construction, of the type shown in International PatentApplication No. PCT/AU01/01036, or may be flexible, of the type known asPadman Bay outlets, or a combination thereof. The free end 58 of barriermember 46 is pivotally attached to pivot pin 24 of linear drive member12 of cable drive device 10 of FIGS. 1 to 5. Support member 29 issecured to a frame member 60 across channel 50. An electric motor 62 iscoupled to axle 26 to allow rotation of cable drum 14.

FIG. 8 shows a variation of FIG. 7 where a pair of cable drive devices10 are used. In this embodiment, electric motor 62 has an extended shaft64 to allow rotation of the axles of both cable drive devices 10. Ifrequired, separate electric motors could be used. The embodiment is notlimited to two cable drive devices 10 as any numbers may be used to suitthe width of the channel 50. FIGS. 7 and 8 show use of a rigidconstruction of barrier member 46.

FIGS. 9 to 11 show the operation of barrier member 46 using the cabledrive device or devices 10. FIGS. 9 to 11 show barrier member 46 havinga rigid base member 52 and flexible side members 54, 56. FIG. 9 hasbarrier member 46 in the closed position with linear drive member 12fully extended in the upward direction. As barrier member 46 is lowered,water flows over the free end 58 of base member 52 in a controlledmanner (FIG. 10). Full flow of water is obtained when linear drivemember 12 is fully extended in the downward direction (FIG. 11). Lineardrive member 12 will be partially immersed in the water, which can be aharsh environment for such devices. In prior art devices it iscommonplace to use gear mechanisms, which do not suit being immersed orbeing exposed to water. Gears can jam and the gear teeth can wearresulting in drive backlash. The cable drive devices 10 do not sufferthese disadvantages and allow a more accurate positioning of barriermember 46 to assist in superior measurement.

FIGS. 12 to 16 are very similar in construction and operation to theembodiment shown in FIGS. 7 to 11. In this embodiment a dam wall 66extends across the channel and barrier member 46 is pivotally attachedto the bottom of dam opening 68 rather than at the bed or base 48 ofchannel 50.

Although the cable drive device 10 of FIGS. 1 to 5 has been shown withreference to its use in the irrigation field in FIGS. 7 to 16 its use isnot limited to that environment. Cable drive device 10 can be used whereany mechanical movement is required.

FIGS. 17 to 22 illustrate an embodiment of a fluid control barrier 70,which is attached to the end 72 of a pipe 74. Pipe 74 is shownvertically disposed but could be readily disposed horizontally, or atany other desired angle. The fluid control barrier 70 can also beadapted to be located within pipe 74 and the embodiment described is notlimited to the position or orientation shown in FIGS. 17 to 22. A flange76 at the end of pipe 74 provides attachment to a flange 78 of fluidcontrol barrier 70. A sealing lip 80 on flange 78 allows the sealingthereto of a pair of semi-circular plates 82, 84 forming a barriermember. The plates 82, 84 are joined along their diametric sides byhinge 86 to open and close fluid control barrier 70 and form abi-foldable barrier member. Hinge 86 is fixed and constrained by frameelements 88, 90 of frame 92. A pair of cross-members 94, 96 completeframe 92. Plates 82, 84 fold in the direction of flow towards thecentreline when opening and into the flow away from the centreline whenclosing.

In order to open and close plates 82, 84 a pair of struts 98, 100downstream of pipe 74 are pivotally attached to plates 82, 84 at one endand are pivotally attached at the other end to a threaded journal 102 atthe other end to form a thrust point. Journal 102 is coupled to athreaded member 104 supported by bearings 106, 108 in respectivecross-members 94, 96. Rotation of the end 110 of threaded member 104will result in opening and closing of fluid control barrier 70 asindicated by arrows 112.

FIGS. 17 to 19 show plates 82, 84 pressed onto sealing lip 80 to preventescape of water from pipe 74. Turning end 110 of threaded member 104will cause threaded journal 102 to move up threaded member 104, asthreaded journal 102 is constrained from rotating. The upward movementof threaded journal 102 will lift struts 98, 100, and plates 82, 84 willthus lift away from pipe 74 to open fluid control barrier 70, as shownin FIGS. 20 to 22. In this configuration the fluid control barrier 70can be used for flood irrigation where water flows out pipe 74 and ontothe ground. End 110 can be turned by hand or coupled to a rotation meanse.g. motor or axle (not shown) controlled by irrigation automation (notshown). By turning end 110 in the opposite direction the plates 82, 84will pivot towards sealing lip 80 to stop water flow.

It is evident that other forms of movement of the plates 82, 84 can beutilised and the invention is not limited to the embodiment shown inFIGS. 17 to 22. FIGS. 23 to 28, FIGS. 31 to 36 and FIGS. 37 to 42disclose various embodiments to move plates 82, 84. FIGS. 23 to 28 havestruts 98, 100 replaced by cable drive devices 114, 116, described withreference to FIGS. 1 to 5. Threaded member 104 has been replaced by arotatable shaft 118 coupled to the axles of cable drive devices 114, 116and supported by frame elements 88, 90. The operation is very similar tothat shown in the embodiment of FIGS. 17 to 22 where rotation of shaft118 will result in the opening or closing of plates 82, 84. The fluidcontrol barrier 70 can also be adapted to be located within pipe 74 andthe embodiment described is not limited to the position or orientationshown in FIGS. 23 to 28.

The embodiment shown in FIGS. 31 to 36 is very similar to the embodimentshown in FIGS. 17 to 22. In this embodiment a cable drive device 120,described with reference to FIGS. 1 to 5, replaces threaded member 104.Threaded journal 102 is not required as struts 98, 100 can be directlymounted to pivot pin 24 of cable drive device 120. The support member 29of cable drive device 120 is mounted to cross-member 94. A drive shaft(not shown) is coupled to central axle 26 for rotation of cable drum 14resulting in opening and closing of plates 82, 84. The fluid controlbarrier 70 can also be adapted to be located within pipe 74 and theembodiment described is not limited to the position or orientation shownin FIGS. 31 to 36.

The embodiment shown in FIGS. 37 to 42 has a completely differentactuation mechanism when compared with the embodiments of FIGS. 17 to 28and FIGS. 31 to 36. In this embodiment a threaded screw member 122 issupported in journals 124, 126 in frame elements 88, 90. Threaded screwmember 122 has opposing threads 128, 130 separated by an unthreadedsection 132. A pair of rotatable journals 134, 136 are mounted onrespective plates 82, 84 and equispaced from hinge 86. A pair ofthreaded journals 138, 140 are threadably attached to respective threads128, 130 on threaded screw member 122 and equispaced from unthreadedsection 132. A first pair of equal length struts 142, 144 are pivotallymounted to rotatable journal 134 at one end and to threaded journal 136at the other end. A second pair of equal length struts 146, 148 arepivotally mounted to rotatable journal 134 at one end and to threadedjournal 136 at the other end. The points of attachment to each plate 82,84 are along the radial axis that bisects the semicircle. The locationof the position of rotatable journals 134, 136 can vary and may bedetermined on the basis of the specific force loading of the actuationmechanism and what is optimal for the actuation mechanism. From theclosed position of plates 82, 84 shown in FIGS. 37 to 39, the shaft end150 of threaded screw member 122 can be rotated. As the threadedjournals 138, 140 are constrained from rotating, the threaded screwjournals 138, 140 will move outwardly along respective threads 128, 130,as evident from FIGS. 40 to 42. Struts 142 to 148 will pivot and causeplates 82, 84 to be lifted and open the fluid control barrier. Turningthe shaft end 150 in the opposite direction will reverse the movementand plates 82, 84 will be moved towards the closed position. The fluidcontrol barrier 70 can also be adapted to be located within pipe 74 andthe embodiment described is not limited to the position or orientationshown in FIGS. 37 to 42. The cable drive device depicted in FIG. 6 couldreplace the outward and inward movement of threaded journals 138, 140along threaded screw member 122.

The embodiment shown in FIGS. 29 to 30 is very similar to the embodimentshown in FIGS. 31 to 36. The major difference is that instead of havingplates 82, 84 mounted at the end of pipe 74, plates 82, 84 are mountedinside pipe 74. The other difference is that the cable drive 120 of thetype described in FIGS. 1 to 5 is located inside pipe 74 rather thanbeing externally mounted. An annular ring 152 on the inner circumferenceof pipe 74 replaces sealing lip 80. Annular ring 152 has a pair ofprotuberances 154 to receive the central pin of hinge 86 to fix theposition of plates 82, 84. Plates 82, 84 are moved by the longitudinalmovement of linear drive member 12 which is pivotally attached to struts98, 100. Cable drum 14 has an axle 156 extending through pipe 74 andsupported in bearings or journals 158, 160 in, or on, pipe 74. Rotationof the end 162 in the direction of arrow 164 will open the valve bylifting plates 82, 84 from its sealed position on annular ring 152 andallow flow of water through pipe 74 in the direction of arrow 166. It isevident that other actuation mechanisms can be utilised in relation tothe mounting of plates 82, 84 inside pipe 74. For example, theembodiment shown in FIGS. 23 to 28 may be used.

The embodiment shown in FIGS. 45 to 48 differs from the embodimentsshown in FIGS. 17 to 28 and FIGS. 29 to 42, in that fixed hinge 86 isreplaced by a floating hinge 168. In this embodiment the hinge 168 isfree to move in the direction of the pipe 74 centreline axis and remainperpendicular to the axis. The valve device can be used at pipe inletsand pipe outlets as well as internal to the pipe 74 as shown in thisembodiment. A threaded screw member 170 is supported in journals 172,174 in pipe 74. Threaded screw member 170 has opposing threads 176, 178separated by an unthreaded section 180. A first pair of equal lengthstruts 190, 192 are pivotally mounted to an unthreaded section 194 ofthreaded screw member 170 at one end and to respective plates 82, 84 atthe other end. A second pair of equal length struts 196, 198 arepivotally mounted to an unthreaded section 200 of threaded screw member170 at one end and to respective plates 82, 84 at the other end. Thepivotal attachment of struts 190, 192, 196 and 198 to respective plates82, 84 is along, or near to, the centroidal axis of the semi-circularplates 82, 84. It is also possible to have only one set of struts, whichcould be pivotally attached to the central unthreaded section 180.

In this embodiment the fluid pressure load associated with thesemi-circular plates 82,84 is transferred to the threaded screw member170 through the struts 190, 192, 196 and 198. A key aspect of thisembodiment is the location of pivotal load supporting struts 190, 192,196 and 198 at or near the centroidal axis. Supporting the plates 82, 84at the centroidal axis means the net fluid pressure forces are equaleither side of the centroidal axis of each semi-circular plate 82, 84.The resultant effect is that the net force in opening or closing theplates 82, 84 is minimal and largely those associated with thefrictional force in moving the hinge 168. This will substantially reducethe power requirements of a motor (not shown) to open and close thefluid control barrier. A small solar powered motor could be used.

The movement of hinge 168 in this embodiment uses a pair of threadedjournals 182, 184 that are threadably attached to respective threads176, 178 on threaded screw member 170 and equispaced from unthreadedsection 180. A first strut 186 is pivotally mounted to hinge 168 at oneend and to threaded journal 182 at the other end. A second strut 188 ispivotally mounted to hinge 168 at one end and to threaded journal 184 atthe other end.

FIGS. 45 and 47 show the closed position whilst FIGS. 46 and 48 show theopen position of the fluid control barrier. From the position shown inFIGS. 45 and 47 the threaded screw member 170 is rotated which resultsin threaded journals 182, 184 moving towards the centre of pipe 74 andpulling struts 186, 188 towards each other. This movement pushes hinge168 away from threaded screw member 170 to release plates 82, 84 in afolding action from seal 202 to open the fluid control barrier. Aspreviously discussed the net force in opening or closing the plates 82,84 is minimal and largely those associated with the frictional force inmoving the hinge 168 by struts 186, 188. Struts 190 and 192 and struts196 and 198 will be drawn towards one another as shown in FIGS. 46 and48.

In addition, the positioning of the struts 190, 192, 196 and 198 onplates 82, 84 with a slight location bias either side of the centroidalaxis can result in a resultant force with a bias towards either selfclosing or self opening depending on what side of the axis is thelocation of the pivotal connection of the struts 190, 192, 196 and 198.A similar result can be obtained by offsetting the mounting point of thestruts 190, 192, 196 and 198 above the surface of said plates 82, 84 andslightly away from the centroidal axis.

In a further embodiment threaded screw member 170 could be replaced byan unthreaded member and threaded journals 182, 184 replaced by annulardrive rings which could be controlled by individual actuator members orby a cable drive device as shown in FIG. 6.

The definition of Centroid and Centroidal Axis: The Centroid is definedas the geometric centre or centre of mass of an object. For the purposesof this application the surface area either side of the centroidal lineare equal and therefore the net pressure forces either side of thecentroidal line of a semi-circular plate are equal.

The Centroidal axis is parallel to the straight edge of a semi-circularshaped plate and at a distance of y from the straight edge and where;

y=4R/3π

Where R is the radius of the semicircle.

The embodiments shown in FIGS. 49 to 64 show different actuator devicesto move floating hinge 168 as described in FIGS. 45 to 48.

FIGS. 49 to 52 show a similar fluid control barrier to that shown inFIGS. 45 to 48. In this embodiment movement of hinge 168 is by a pair ofcable drive devices 10 as described with reference with FIGS. 1 to 5. Anon-threaded shaft 204 passes through pipe 74 to replace the threadedscrew member 170. Struts 186, 188 are not required to move against hinge168. Cable drive devices 10, from the closed position, pull hinge 168.The embodiment shows a pair of cable drive devices 10 at opposing endsof hinge 168 but a single centrally located cable drive device 10 couldalso be used. The pivotal attachment of struts 190, 192, 196 and 198 torespective plates 82, 84 is along, or near to, the centroidal axis ofthe semi-circular plates 82, 84 as described with reference to FIGS. 45to 48. FIGS. 49 and 51 show the closed position of the fluid barrierwhilst FIGS. 50 and 48 show the open position of the fluid controlbarrier. From the position shown in FIGS. 49 and 51 the axles 156 arerotated causing the linear drive members 12 to pull hinge 168 axiallyaway and pull struts 186, 188 towards each other. This movement pullshinge 168 to release plates 82, 84 in a folding action from seal 202 toopen the fluid control barrier. Struts 190 and 192 and struts 196 and198 will be pulled towards one another as shown in FIGS. 50 and 52.Again the net force in opening or closing the plates 82, 84 by cabledrive devices 10 is minimal.

FIGS. 53 to 64 show an embodiment that is very similar to the embodimentshown in FIGS. 49 to 52 except that the fluid control barrier is locatedat the end of pipe 74 rather than being located inside pipe 74. The pairof cable drive devices 10 shown in FIGS. 49 to 52 has been reduced to asingle device 10, which is external to pipe 74. The non-threaded shaft204 is constrained by journals in frame elements 88, 90 of frame 92 andis drivingly coupled to cable drum 14. A pair of hinge struts 212 arepivotally coupled at one end to linear drive member 12 and to the otherend to hinge 168. The pivotal attachment of struts 190, 192, 196 and 198to respective plates 82, 84 is along, or near to, the centroidal axis ofthe semi-circular plates 82, 84 as described with reference to FIGS. 45to 48. In the closed position shown in FIGS. 53 to 56 the plates 82, 84will be pressed against seal 202 to prevent escape of water. Therotation of shaft 204 will result in rotation of cable drum 14 whichwill move linear drive member 12 downwardly. This downward force willpush hinge 168 downwardly to the position shown in FIGS. 57 to 60 toopen the fluid control barrier. Plates 82, 84 will pivot away from seal202 in view of their pivotal connection to hinge 168. Struts 190 and 192and struts 196 and 198 will be pulled towards one another to push plates82, 84 into pipe 74. FIGS. 61 to 64 show the fluid control barriercompletely open with plates 82, 84 having an acute angle between themand collapsing around struts 190, 192, 196 and 198. As discussedpreviously the supporting of plates 82, 84 at the centroidal axis meansthe net fluid pressure forces are equal either side of the centroidalaxis of each semi-circular plate 82, 84. The resultant effect is thatthe net force in opening or closing the plates 82, 84 is minimal andlargely those associated with the frictional force in moving the hinge168.

Additional and/or alternate mechanisms to those described could be usedto actuate the plates 82, 84 by providing force on hinge 168. The manskilled in the art could readily select such mechanisms and theinvention is not limited to the mechanisms shown for the fluid controlbarrier.

The fluid control barriers described hereinbefore using a pair ofsemi-circular plates barriers 82, 84 pivoting at hinge 86 or 168 andpositioned across the diameter of pipe 74 will bisect the flow movingthrough pipe 74. The advantage of this type of fluid control barrier isthat there is a symmetrical flow profile generated perpendicular to thehinge 86 or 168. A symmetrical flow profile will suit the location of aflow meter using ultrasonic transit time flow measurement techniquesdiscussed in Wikipedia and in International Patent Application No.PCT/AU2010/001052, the contents of which are incorporated herein. Theinvention allows a flow meter to be located immediately upstream offluid control barrier and is unique as it is often necessary to locateflow meters some distance upstream of a fluid control barrier or valve(typically up to five pipe diameters in order that a symmetricalvelocity profile is developed. Traditional valve mechanisms such as abutterfly valve or a gate valve do not generate a symmetrical velocityprofile immediately upstream of the valve.

A further embodiment to the bi-folding plates 82, 84 is to streamlinethe shape of the barrier surface (upstream) to lessen the drag andtherefore the energy loss of the fluid as it traverses the valve. Whenthe valve is fully open and the two barriers are adjacent and near inline with the pipe centreline, the cross-sectional profile wouldapproximate a streamlined ‘tear drop’ shape. The embodiment shown inFIGS. 65 to 79 illustrates the tear drop shape formed by the bi-foldingplates 82, 84. Plates 82, 84 provide a clam shell type configurationeach having a bulge 220 at the hinged end and tapering towards the shaftend 222. When plates 82, 84 are in the fully open position as shown inFIGS. 75 to 79 a basic tear drop profile will be formed by the exteriorsurfaces of plates 82, 84. Plates 82, 84 wilt form a clam shell whichwill substantially enclose struts 190, 192, 196 and 198 to reducefrictional drag of the water.

In the embodiments shown with pipe 74 and semi-circular plates 82, 84the invention is not limited to a complementary circular construction.Pipe 74 could be square or any other closed profile with plates 82, 84being configured to match the pipe profile. In non-circular profiles thehinges 86, 168 can be located midpoint to provide symmetrical ornon-symmetrical plates 82, 84.

The centroidal axes can be readily determined to maintain the reducedforce to move hinge 168.

The invention will be understood to embrace many further modificationsas will be readily apparent to persons skilled in the art and which willbe deemed to reside within the broad scope and ambit of the invention,there having been set forth herein only the broad nature of theinvention and certain specific embodiments by way of example.

1. A fluid control barrier for a pipe comprising: a bi-foldable barriermember for controlling movement of fluid along the pipe and having apair of plates with a hinge along their straight edges to allow foropening and closing of said fluid control barrier; and an actuationmechanism comprising a threaded screw member having a first thread and asecond thread; a pair of threaded journals; a first pair of struts and asecond pair of struts; the pair of plates comprising a first plate and asecond plate; the first thread opposing the second thread; the pair ofthreaded journals comprising a first threaded journal threadinglyengaged with the first thread and constrained from rotating; and asecond threaded journal threadingly engaged with the second thread andconstrained from rotating; the first pair of struts connecting thethreaded journals to the first plate, and the second pair of strutsconnecting the threaded journals to the second plate, such that rotatingthe threaded screw member opens and closes the bi-foldable barriermember.
 2. The fluid control barrier of claim 1 configured to be fittedto an end of a pipe or inside said pipe.
 3. The fluid control barrier ofclaim 1 wherein the opposing threads are separated by an unthreadedsection.
 4. The fluid control barrier of claim 1 comprising a pair ofrotatable journals; the pair of rotatable journals comprising a firstrotatable journal and a second rotatable journal; the first platecarrying the first rotatable journal; the second plate carrying thesecond rotatable journal; each strut of the first pair of struts beingpivotally mounted to the first rotatable journal; and each strut of thesecond pair of struts being pivotally mounted to the second rotatablejournal.
 5. The fluid control barrier of claim 1 comprising a pair ofrotatable journals; the pair of rotatable journals comprising a firstrotatable journal and a second rotatable journal; the first platecarrying the first rotatable journal; the second plate carrying thesecond rotatable journal; each respective strut of the first pair ofstruts having a respective end by which the respective strut ispivotally mounted to the first rotatable journal; and each respectivestrut of the second pair of struts having a respective end by which therespective strut is pivotally mounted to the second rotatable journal.6. The fluid control barrier of claim 1 wherein the rotatable journalsare equispaced from the hinge.
 7. The fluid control barrier of claim 1wherein a respective first strut of each of the first pair of struts andthe second pair of struts is pivotally connected to the first threadedjournal; and a respective second strut of each of the first pair ofstruts and the second pair of struts is pivotally connected to thesecond threaded journal.
 8. The fluid control barrier of claim 1 whereina respective first strut of each of the first pair of struts and thesecond pair of struts has a respective end by which the respective firststrut is pivotally connected to the first threaded journal; and arespective second strut of each of the first pair of struts and thesecond pair of struts has a respective end by which the respectivesecond strut is pivotally connected to the second threaded journal. 9.The fluid control barrier of claim 1 wherein the struts of the firstpair of struts are of mutually equal length; and the struts of thesecond pair of struts are of mutually equal length.
 10. The fluidcontrol barrier of claim 1 wherein the plates are semi-circular platesand attachments points, at which the first pair of the struts and thesecond pair of struts attach to the plates, are along a radial axisbisecting the semi-circular plates.
 11. The fluid control barrier ofclaim 1 configured such that rotating the threaded member to cause thethreaded journals to move outwardly opens the fluid control barrier. 12.The fluid control barrier of claim 1 configured to be fitted to an endof the pipe.
 13. The fluid control barrier of claim 1 configured to befitted to inside the pipe.
 14. The fluid control barrier of claim 1fitted to an end of the pipe.
 15. The fluid control barrier of claim 1fitted inside the pipe.
 16. An arrangement, for a pipe, comprising: aflow meter; and a fluid control barrier comprising a bi-foldable barriermember for controlling movement of fluid along the pipe and having apair of plates with a hinge along their straight edges to allow foropening and closing of said fluid control barrier; and an actuationmechanism comprising a threaded screw member having a first thread and asecond thread; a pair of threaded journals; a first pair of struts and asecond pair of struts; the pair of plates comprising a first plate and asecond plate; the first thread opposing the second thread; the pair ofthreaded journals comprising a first threaded journal threadinglyengaged with the first thread and constrained from rotating; and asecond threaded journal threadingly engaged with the second thread andconstrained from rotating; the first pair of struts connecting thethreaded journals to the first plate, and the second pair of strutsconnecting the threaded journals to the second plate, such that rotatingthe threaded screw member opens and closes the bi-foldable barriermember; the flow meter being arranged to be immediately upstream of thefluid control barrier.
 17. A method of irrigation including utilizing afluid control barrier to control the flow of water; the fluid controlbarrier comprising a bi-foldable barrier member for controlling movementof fluid along the pipe and having a pair of plates with a hinge alongtheir straight edges to allow for opening and closing of said fluidcontrol barrier; and an actuation mechanism comprising a threaded screwmember having a first thread and a second thread; a pair of threadedjournals; a first pair of struts and a second pair of struts; the pairof plates comprising a first plate and a second plate; the first threadopposing the second thread; the pair of threaded journals comprising afirst threaded journal threadingly engaged with the first thread andconstrained from rotating; and a second threaded journal threadinglyengaged with the second thread and constrained from rotating; the firstpair of struts connecting the threaded journals to the first plate, andthe second pair of struts connecting the threaded journals to the secondplate, such that rotating the threaded screw member opens and closes thebi-foldable barrier member.